Static/bitcrusher-like Noise... [usb]

I've not had the greatest experience with the Pod HD500, but I stuck with it as I have seen people getting really good results with it and I know it's just down to me not dialling the right tone in. Today I sat down as usual to do some recording and noticed the sound wasn't right. It was muffled and dull, so I disconnected it.

I reconnected it to my Mac and suddenly now everything sounds like a static/bitcrusher-like noise making it unusable. I've tried power cycling both my Mac and the Pod, but the problem still exists. I'm scared to try another USB port in case the Pod somehow fries it. I don't have anything on hand right now that I can use to make sure no damage has been done to the USB port that the Pod was plugged into. I shall test that once I get home.

I also don't have another Pod USB cable to try.

What is wrong? How can I fix this? I hope the Pod hasn't somehow overloaded and fried my USB port?? I've attached an MP3 to show you this horrible static noise. In this recording it doesn't sound as bad as it usually is. Sometimes the pitch is distorted and wavers between being sharp and flat (kinda like when batteries start to go flat in things can emit sounds, like doorbells, etc. Sorry, that's the best way I can describe it.)

Also to note, before this problem arose, after using the tuner, the same sound happened, gradually getting more violent and then dying off and then everything went back to normal. This doesn't happen now, though, it just stays static-y and distorted.

I'm incredibly worried more about the USB port on my Mac rather than the Pod itself, though. Please help!

Thanks for your reply. I tried headphones and everything was working perfectly so it must have been the Mac. I managed to fix the issue by restarting the audio driver in Garageband for the Pod. Turns out it wasn't as major as it originally seemed, which I'm glad about. I'm a little confused what could have caused the issue in the first place though.

I'm still having the tuning problem, where after turning the tuner off there is huge latency and then the sounds starts to sound like bitcrusher which gradually gets louder and more violent sounding, until dying off and going back to normal. It's not a huge issue as I never tune during a recording, but it is a slight nuisance, kinda like when you get an itchy nose during a solo. Any technical idea what could cause this? It doesn't do it through headphones, so must be an issue with my Mac. I'm not looking to remove it, I'd just like to know why it happens in such a way, and if anyone else has that problem. I'll post a sample if you need to hear it.

I get all sorts of digital sync type things when using my mac.. it seems to happen less at 48k samples.. i think the default is 44.1k not sure if you can change it on garage band... i tend to use the new logic pro x... its pretty awesome!

Yeah, I have noticed that sometimes on my Mac there will be a lot of latency and other times pretty much none at all, even though the environment on my Mac is exactly the same. I usually just turn everything off and go back to the recording later if there's too much latency to work with. Usually the latency just magically disappears then! (I know I should be listening through the headphone port on the Pod, but I don't have any decent monitoring headphones yet, as I just started getting into home recording; quite enjoyable, so far!)

Unfortunately it's not possible to change the sample rate on Garageband, but thanks for the suggestion as I'll be upgrading to a better DAW once I have some money to spare! Garageband is a great place to start for a newbie like me starting to learn the ropes of home recording and mixing, but not sure how it will hold up once I get more experienced. IF I get more experienced, that is!